Tap.



PATENTED JUN HZ 1903.

J No. 729,647. y

F. J. NU-TTING.

' TAP.

APPLICATION FILED 00123, 1902.

lilO MODEL.

UNITED. STATES Patented June 2, 1903.

PATENT OFFICE.

FREDERICK J. NUTTING, OF DAYTON, OI IIO, ASSIGNOR TO THE NATIONALAUTOMATIC TOOL CO., DAYTON, OHIO.

TAP.

SPECIFICATION forming part of Letters Patent No. 729,647, dated June 2,1903. Application filed October 23, 1902. Serial No. 129,426. (Nomodel.) I

To all whom it may concern:

Be it known that I, FREDERICK J. NUTTING, a citizen of the UnitedStates, residing at Dayton, in the county of Montgomery and State ofOhio, have invented certain new and useful Improvements in Taps and I dodeclare the following to be a fulLclear, and exact description of theinvention, such as will enable others skilled in the art to which itappertains to make and use the same, reference being had to theaccompanying drawings, and to the letters of reference marked thereon,which form a part of this specification.

This invention relates to improvements in taps for drillingscrew-threaded openings and possesses the novel and advantageousfeatures hereinafter described and claimed.

The objects of my invention are, first, to provide a tap with a reamerattached thereto, sothat a hole may be reamed and tapped in oneoperation, and, secondly, to provide an implement of the above characterwhich possesses thestructural features hereinafter described andclaimed.

Preceding a detail description of the invention, reference is made tothe accompaning drawings, of which Figure 1 is a vertical longitudinalelevation of my improved tap, showing the tap-j aws c011- tracted. Fig.2 is a vertical longitudinal midsectional elevation of the same, showingthe tap-jaws expanded. Fig. 3 is a sectional elevation showing thetap-jaws contracted, as shown in Fig. 1. Fig. 4. is a transverse sectionon the line 00 a: of Fig. 2. Fig. 5 is a detached view of the retainingband or ring.

In a detail description of the invention similar reference charactersindicate corresponding parts.

A designates a headwhich has four longitudinal grooves B ondiametricallyopposite sides, that receive four tap-jawsC, said jawsbeing pivoted therein at D. These tap-jaws have on their outer exposedsides,at theends opposite to their pivots, cutting-teeth E, which duringthe rotation of the headfA cutscrewthreads in a well-known manner. Thesaid tap-jaws are adapted to-receiveexpanding and contracting movements,respectively, through the expanding-rod F and the cupped contracting orcollapsing cone G. The cone G is essentially not an integral part of therod F, for the reasonsthat it would be impracticalto construct the rodand the cone as integral parts, and, further, by making the conedetachable it may be replacedwhen usage renders it unserviceable. Theextreme end of the enpanding'rod F is reduced in diameter at a ascompared with the portion lying within the hub of the head, and adjacentto said reduced portion a there is an annular tapering or cam surfaceI). In the outward or expanding movement of said rod F this taperingsurface I), coming in contact with the tapering surfaces 0 on the jawsand thence in contact with the straight surfaces 0 of said jaws causessaid jaws-to ride upon the surface of the larger diameter of the rod F,and thereby expand said jaws to their outer or operating position, asshown in Fig. 2. The collapsing or contracting cone G is made fast uponthe smaller portion of the rod F by means of the nut H or otherwise. Theinterior tapering surface e of said cone inthe inward or upward movementof the rod F contracts or draws inwardly the tap-jaws C to the positionshown in Fig. 3.- The ends of said jaws adjacent to the cone Garerecessed, as at g, to enable the rim of the cone to enter as the surface6 moves against the tapering surface f of the jaws. So In thisconnection it will be observed that the tapering surfaces 0 and f areprovided upon opposite edges of what may be properly termed aninwardly-proj ecting offset of each tapjaw, which oifset is of taperingform. I is a retaining-band, which surrounds the head and is securedthereto at a suitable point along said head by means of countersunkscrews I. This band is designed to prevent the tap-jaws C from movingout of their openings B to an unnecessary extent. In the expandingmovement of the said jaws they have the necessary room to move in bymeans of the rccesses'l at opposite points of said retaining-band.

The head A is provided with an exteriorl screw-threaded portion A, whichscrews into a shaft A, thejsaid shaft being mounted in a journal B anddriven by a suitable gearing, as shown. The outer or lower end of the mohead A has secured thereto a reamer which operates to cut the opening inadvance of the thread-cutting operation of the tap, so that the hole isreamed and tapped in one operation. The head A is provided with a seriesof concavities or recesses K, which lie on one side of the cutting-teethE and receive the shavings or cuttings from said teeth during theoperation of the tap. The expanding-rod F may be operated longitudinallyin any suitable manner to spread the tap-jaws O or to bring thecontracting-bone G in a position to close said jaws.

The operation of the tap is briefly described as follows: The s ime isadjusted by lowering or moving out the rod F to the position as shown inFig. 2, which, as before stated, spreads the tap-jaws O to their outeror operative position. The material to be operated upon is elevated ormoved against the reamer J, which cuts the opening for the tap. Thetap-jaws, entering said opening in their eX- panded position, cut thethreads, after which the rod F is moved in an opposite position to bringthe contracting-cone G against the surfaces f of said jaws and thelargest part of the rod F away from the surfaces 0 of said jaws. Thetool is then removable by lowering the material operated upon.

Having described my invention, I claim A thread-cutting tool comprisinga longitudinally-grooved rotatable body having a central openingtherethrough and provided at one end with a reamer formed with anopening in axial alinement with that through the body, a series oftap-jaws pivotally supported at one end in the grooves of the body, andeach of said jaws being provided upon the inner side thereof, and at orcontiguous to its swinging end, with an inwardly-projecting offset of atapering form with separate inclines or bevels inclining in the samedirection, a retaining band encircling the head and the series of jawstherein, a reciprocatory expanding rod movable in the openin g throughthe head and provided at a point contiguous to one end with an annularconesurface for engagement With the inclines or bevels at one edge ofthe offsets of the jaws, and a cupped cone detachably mounted on oneextremity of the rod and having a bearing within the reamer-opening,said cupped cone being designed to take over the offsets of the taps andengage with the inclines or bevels at the opposite edge of such oifsets.

In testimony whereof I affix my signature in presence of two Witnesses.

FREDERICK J. NUTTING.

